
HITACHI 11
Table 1.3
Pin Functions (cont)
Type
Bus
control
(cont)
Symbol
RAS
Pin No.
52
I/O
O
Name and Function
Row address strobe: DRAM row-address strobe-timing
signal.
Column address strobe high: DRAM column-address
strobe-timing signal outputs low level to access the
upper eight data bits.
CASH
47
O
CASL
49
O
Column address strobe low: DRAM column-address
strobe-timing signal outputs low level to access the
lower eight data bits.
RD
WRH
57
O
Read: Indicates reading of data from an external device.
56
O
Upper write: Indicates write access to the upper eight
bits of an external device.
WRL
55
O
Lower write: Indicates write access to the lower eight
bits of an external device.
CS0
–
CS7
AH
46–49,
51–54
O
Chip select 0–7: Chip select signals for accessing
external memory and devices.
61
O
Address hold: Address hold timing signal for a device
using a multiplexed address/data bus.
HBS
,
LBS
WR
20, 56
O
Upper/lower byte strobe: Upper and lower byte strobe
signals. (Also used as
WRH
and A0.)
55
O
Write: Brought low during write access. (Also used as
WRL
.)
DMAC
DREQ0
,
DREQ1
66, 68
I
DMA transfer request (channels 0 and 1): Input pins for
external DMA transfer requests.
DACK0,
DACK1
65, 67
O
DMA transfer acknowledge (channels 0 and 1):
Indicates that DMA transfer is acknowledged.
16-bit
integrated-
timer pulse
unit (ITU)
TIOCA0,
TIOCB0
51, 53
I/O
ITU input capture/output compare (channel 0): Input
capture or output compare pins.
TIOCA1,
TIOCB1
62, 64
I/O
ITU input capture/output compare (channel 1): Input
capture or output compare pins.
TIOCA2,
TIOCB2
83, 84
I/O
ITU input capture/output compare (channel 2): Input
capture or output compare pins.
TIOCA3,
TIOCB3
85, 86
I/O
ITU input capture/output compare (channel 3): Input
capture or output compare pins.
TIOCA4,
TIOCB4
87, 89
I/O
ITU input capture/output compare (channel 4): Input
capture or output compare pins.